Changes since the 2021082501 release:

• Settings: add back past GrapheneOS feature for toggling whether secondary users can install new apps
• Vanadium: update Chromium base to 92.0.4515.166
• Vanadium: update Chromium base to 93.0.4577.62
• Vanadium: hide sign in preference when disallowed
• Vanadium: disable using Play services as a source for certain Google fonts
• automatically disable UART debugging when flashing factory images (GrapheneOS already extends the notification about it to production builds)
• Auditor: update to version 29
• SetupWizard: properly disable system UI navigation for the entire setup process
• kernel (Pixel 4a (5G), Pixel 5): drop unnecessary Wi-Fi driver change from our previous downstream security fixes
• Pixel 4, Pixel 4 XL: enable saturated color option